Dont have a camper trailer - and im not a mum or a dad and when one of us goes any where in the car both of us go
But I agree with you there derek and if I had a camper I would definately have one installed on the trailer - and I would have a fire blanket.
As it is I keep a fire blanket at the campsite and naturally a bucket of water next to the fire when we have a fire (it continually amazes me how many people dont do this!)
Just be careful when purchasing a fire extinguisher that you get the correct type from memory its an AB or ABC type that you need.
Also remember to periodically take the extinguisher out of its bracket inspect for leakage &/or rust, check the gauge (i wouldnt own an extinguisher without a gauge) to make sure its still fully charged and give it a good shake then replace it back in the holder